>14> ANALYSIS OF IRON SPAR. 



its saturation by coml)nstion at the mean temperature and 



gave 77 base pressure '01549 of a orain of oxigen ; and 100 p'-irts of soda, 

 to 23 oxigen. J- i 1 • • 11 • J ' t- ^^ t 



■according to this proportion, would consist nearly ot 77 ba- 

 sis, and 23 oxigen. 



Sever?.! other X),e experiments, which have been iust detailed, arc 



experiments i - i • i i 



made. those m which the largest quantities of materials were em- 



ployed ; I have compared their results, ho?«?ever, with the 

 results of several others, in wliidi the decomposition of wa- 

 ter was performed with great care, but in \i»h;ch the pro- 

 portion of the bases was still more minute: the largest 



whole quantity of oxigen indicated by these experiments w"as, for 



Gbaseto lox- ^^jj^l^ j^ and for soda 26 Darts in 100, and' tV.e smallest 



igen tor pota-h ' . ' 



and 7 base to 2 13, and 19; and comparing all the estimations, it will pro- 

 oxigenfoisoda bably be a good approximation to the truth, to consider 

 probably near , ^ , !> i , • . /• ■ 



the truth. potash as composed of about 6 parts basis and I or oxigen; 



and soda, as consisting of 7 basis and 2 oxigen. 

 fT'o he concluded in our next. J 



From a corn 

 parison of the 



XI. 



Remarks 07t Iron Spar: by Mr. Bergman^. 



R. Haiiy, having been informed in a letter from Mr. 



found no' per- K'^^ssenfratz, that Mr. Berthier, in his analysis of iron spar, 



<eptible por- had found merely inperceptible traces of the presence of 



L'on spar. lime, sent to the laboratory of investigation belonging to 



the Museum two pieces of this ore, one of whicli was black, 



the other white, both regularly crystallized and free from 



any gangue, that they might be examined for the existence 



of lime. The following are the results of this preliminary 



examination. 



Black iron spar. 

 Iron, at a minimum • • 63 



_, ^ Carbonic acid united vvith the iron-* iG-Q 



Component ^ i . /■ i ■ „ 



part/of black Carbonate of hme • ■ 5 



iron spar, ac- Water of Crystallization l6'l 



cording .to the —__«_». 



author: 100 



' * Jo-firnal 4cs Mines, No. lU, p. 241. 



White 



